Silanization of multi-walled carbon nanotubes and the study of its effects on the properties of polyurethane rigid foam nanocomposites

In the current report, surface modification of hydroxylated multi-walled carbon nanotubes (OH-MWCNTs) was done by silanization with 3-aminopropyltriethoxysilane (APTS) and dipodal silane (DSi). Then, rigid polyurethane (PU) foam nanocomposites were prepared by silanized MWCNTs to investigate the effects of the silane-modified MWCNTs on the mechanical, thermal, and morphological properties of the nanocomposites. Morphological studies showed that the addition of silanized MWCNTs to the PU matrix increases the cell density of nanocomposites. The obtained data from SEM analysis also showed the nanoparticles dispersion for 1.5 wt% of DSi-MWCNT (dipodal silane - MWCNT) loading when compared to same loading level of Si-MWCNT (APTS - MWCNT) and resulted in improved mechanical properties of nanocomposites. The results of mechanical tests showed that the Young's moduli as well as tensile strengths were improved due to the presence of strong interfacial interaction between the PU matrix and the nanotubes in PU nanocomposites.